The point-to-point protocol (PPP) provides a standard method for transporting multi-protocol datagrams over point-to-point links. A mobile station needs to maintain PPP connectivity while the mobile station is providing seamless data connectivity in a mobile environment. Once the mobile station has established a PPP session and is assigned an IP address, its data service enters dormant state when it has no data to send or receive. In such conditions, mobile station monitors change in network parameters in order to determine whether it needs to reconnect its data service in order to maintain PPP connectivity. In a CDMA network, whenever the mobile station detects changes in certain network parameters such as the System ID (SID) or Network ID (NID) or a new packet zone identifier, the mobile station needs to re-establish the PPP link layer pursuant to the IS-707 standard. The reconnection attempt may include sending a message on the control channel or making a data call on dedicated traffic channel.
In certain scenarios, when the mobile station is in a boundary area, it may move back and forth between two SIDs/NIDs and be required to perform repeated PPP reconnections. If the network does not expressly provide the number of packet zone identifiers that the mobile station is to keep, then the mobile station only maintains one entry for the packet zone and in such cases, a similar ping-pong scenario would happen between two packet zone boundaries.
Even when the mobile station is stationary in a border area, it is possible that the mobile station could ping-pong between two boundary areas due to the fluctuations in radio frequency coverage.
Under such circumstances, the mobile station continually makes data calls in order to reconnect its packet data service. This results in wasting valuable battery life as well as causing an extra burden on network resources.